This application seeks continued support for The PhD Program in Complex Systems and Brain Sciences initiated in 1995 under the joint auspices of NIMH and Florida Atlantic University. The need for such a program was recognized by a previous review and may be paraphrased as follows: "As neuroscientists learn more and more about the subcellular and biophysical properties of the nervous system, the complex systems approach seeks to characterize the behavior of integrated units, including neural networks, intact and isolated portions of the spinal cord, whole brain functioning and behavior. The approach is truly interdisciplinary. . . [and] the time is ripe for a fully integrated Training Program in this area." Among the reasons why this Training Program warrants continued support are the following developments that have occurred in the last budget period: 1) The number of well qualified applicants has grown, and far outstretches the number of fellowships available (a ratio of about 10:1); 2) The number of outstanding Core Faculty recruited specifically for this PhD Program has increased by four in the last 3 years alone, enhancing both the depth and breadth of the curriculum; 3) The level of research productivity of past and current fellows is outstanding, and reflects an unusual degree of collaboration between both faculty and students, many of whom come originally from different disciplines; 4) Ten PhDs have been awarded with two more scheduled to finish before September 2001; 5) Graduates of this Program now occupy excellent positions in Universities and other institutions, attesting to the broad range of skills and high level of training provided; 6) A new 20,000 sq. ft. facility to house the Training Program has been constructed that, due to a special collaboration with the private and corporate sector, includes capabilities for cutting-edge, real-time imaging of the human brain (fMRI); 7) The level of University support for this Program -the only one of its kind on campus- is considerable, and includes tuition waivers for both in-state and out-of state fellows, and the provision of at least a matching number of assistantships; and 8) the assignment of a new endowed Chair in Complex Systems and Brain Sciences to this Training Program, which, along with commitments to make a number of junior hires will further enhance training opportunities for pre-and postdoctoral fellows.